I once had a contest with some friends who were AK-47 fanatics to demonstrate the difference between the 2 weapons. My philosophy about the M-16/AR configuration was and still is that it lends itself better to a sustained firefight than the AK. The reasons for this are quite simple, and anyone that has shot 3-gun matches will tell you this. the AR was designed to have all of the major controls (safety, fire selector, charging handle, mag release) close and able to be operated with a single hand. With practice, one can shoot the weapon very quickly and accurately, keeping the weapon on target, even while reloading which can be a critical juncture in any gunfight. Just try and do that with an AK. For the test, I placed 3 IPSC targets at 50 yards for each weapon. The drill was simple; at the signal engage each target with 5 rounds each, then change magazines, then engage the next target with 5 rounds each, then reload and the final target. Time to complete the drill would be noted, as well as the number of valid "A" zone hits (hits in center mass for the non-IPSC crowd). At the sound of the buzzer, we began. The AR Carbine I owned at the time was simple, it had a flat-top mount SS Bull Barrel topped with a C-more sight, and a stock trigger. the barrel was uncompensated in any way other than weight. the AK was a Norinco model, plain vanilla. I ran through the first 5 shots and then reloaded, taking about 1.5 seconds per reload (sure can't do that anymore) and finished in about 13 seconds. When I had dumped all of my rounds and finished, the AK was only about 2 rounds into his second mag. He finished in 23 seconds. We then went to the targets to observe the results. All but 4 of my rounds hit the "A" zone, while he only managed to place 8 shots in the "A" zone, with 6 misses. At that point, I rested my case. I am certainly not bashing the AK, because it has its place in the world of combat. And I know the AR has some drawbacks as well, mostly from the design, which have been recently corrected through the re-engineering of the cycling process by going from a gas-pressure to a gas-piston type system. As far as calibers go, just about any caliber can be had for the AR, with the same ergonomic features and accuracy.
So don't hate the AR; it is rapidly becoming the 1911 of assault weapons.......